Lamp-socket.



R. B. BENJAMIN.

LAMP SOCKET.

APPLIOATION FILED APB.19, 1912.

Patented Dec. 24, 1912.

and lamp-retaining UNITED STATES PATENT OFFICE.

REUBEN B. BENJAMIN, OF CHICAGO, ILLINOIS.

LAMP-SOCKET.

Specification of Letters Patent. Patented Dec, 24 1912,

Application filed April 19, 1912. Serial No. 691,970.

T 0 all whom it m 413 concern Be it known that I, REUBEN B. BENJA- MIN,a citizen of the United States, residing at Chicago, in the county ofCook and State of Illinois, have invented new and useful Improvements inLamp-Sockets, of which the following is a full, clear, concise, andexact description, reference being had to the accompanying drawing,forming a part of this specification.

My invention pertains to lamp retaining devices for use in connectionwith electric lamp sockets and the like.

Where lamp sockets are used in places where there is much vibration, orwhere the sockets are subjected to jars and sudden movement, it is foundthat the lamps will gradually become loose, so that contact willultimately cease to be made between the center contacts of the lamps andthe sockets. Dangerous arcing frequently results from this cause.Special sockets have, from time to time, been devised with a view toobviating this trouble; but, in some cases, these special sockets aresubject to the disadvantage that it was difiicult to remove the lampwhen it was desired to do so, and, in other cases, the constructionsemployed were too expensive or complicated to meet the commercialrequirements.

It is the principal object of my invention, therefore, to provide anelectric lamp socket having a simple and inexpensive retaining devicefor preventing the lamp from shaking loose, the retaining device beingsuch as to permit the lamp to be easily introduced into, or withdrawnfrom, the socket, when desired.

A lamp-retaining device constructed in accordance with my invention, asapplied to a socket of the kind described in my pending applicationSerial No. 590,502, filed November 3rd, 1910, is described, by way ofexample, in the following specification, and shown in the accompanyingdrawings, in which:

Figure 1 is a sectional elevation of the lamp socket having alamp-retaining device constructed in accordance with my inventionapplied thereto; Fig. 2 is a side elevation of the threadedlamp-receiving contact device, separated from the remainder of t esocket; Fig. 3 is a side elevation of the parts shown in Fig. 2 turnedthrough an angle of ninety degrees from the position shown in thatfigure; Fig. 4 is a Of these, the upper member 12 carries a centercontact 14, upon the lower side thereof, and also a spring contact clip15 for receiving a contact tongue 16 which extends upward from thethreaded contact 17. The contact 17 has secured thereto a flange 18which is riveted to the lower member 13. The upper member 12 carriesbinding terminals (not shown) which are in electrical connection withthe center contact 14 and the contact clip 15. As has been said, thesocket is of the kind described in my pending application, referred toabove, and does not, in itself, form a part of the present invention;and it does not, therefore, require further description here.

The threaded contact 17 has formed therein two oppositely disposed slots19 extending in the direction of the thread thereof. Through these slotsextend two friction shoes 20, the inner edges of which are suitablyshaped to engage closely the thread of the lamp-base, when a lamp isinserted into the socket. The friction shoes 20 are prevented frompassing completely through the slots 19, by means of ears 21 formed upontheir ends, which engage the outer surface of the contact 17, beyond theends of the slots 19. Spring pressure is applied to the friction shoes,to cause them to engage resiliently against the thread of the lamp base.

The friction shoes 20 are provided, at their outer edges, with lugs 22,which enter corresponding slots 23 formed in a pair of spring straps 24,which latter are locked together at their ends so as to surround thecontact 17. Each of the spring straps 24 is larger at one end than atthe other; and the large end 25 is formed with an aperture 26 having atongue 27 at the front part thereof. The smaller end 28 is of a widthsomewhat less than the width of the aperture 26 in the larger end, andis formed with a hole 29 of corresponding size to the tongue 27. Inassembling the parts, the friction fore,

shoes are first placed in the slots 19 of the contact 17; and the springstraps 24 are then placed on them, with the lugs 22 in the slots 23. Thetwo straps 24 are then locked together by inserting the small end 28 ofeach strap into the aperture 26 in the large end of the other, so thatthe tongues 27 enter the holes 29. In order that this locking operationmay be performed, it is necessary that the straps be sprung inward attheir ends. The resulting tendency of the straps to resume their normalshape, therehas the efiect that a considerable inward .spring pressureis exercised upon the friction shoes.

The inner edges of the friction shoes 20 are normally located within theplane of the thread of the contact 17 but when a lamp is [inserted inthe socket, its base forces the shoes outward. against the action of thespring straps 24:, the shoes thereafter bearing frictionally against thelamp-base. The turning effort required to introduce, or withdraw, thelamp is, of course, greater than would be the case if no retainingdevice were employed; but, nevertheless, the operation can be effectedwith case. When the lamp is in the socket, the friction shoes 20 exert aconsiderable pressure upon the lampbase, and effectively prevent thelamp from shaking loose.

While I have described and shown one embodiment of my invention, it isto be understood that the same may be embodied in other constructions,within the scope of the appended claims.

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent, is: v

1. In a lamp socket, the combination with a threaded lamp contact havingan aperture formed therethrough, of aspringreadily withdrawn,

- 2. In a lamp socket, the combination with pressed clamping memberextending through sa1d aperture so as to exert a spring pressure againstthe lamp base when a lamp is lnserted into the socket, whereby the lampis firmly maintained in position, but may be if desired.

a threaded lamp contact, of a friction shoe adapted to engage the lampbase when a lamp is inserted into the socket, means for exerting aspring pressure upon said friction shoe so as to force the same intoengagement with the lamp base, whereby said lamp 1s firmly maintainedinsaid socket but may be readily removed therefrom when desired.

3. In a lamp socket, the combination with a threaded lamp contact, of apair of friction shoes disposed at opposite sides of said lamp contactand adapted to engage the lamp base when a lamp is inserted into thesocket, and means for exerting a spring pressure upon said frictionshoes so as to force them into engagement with the lamp base, wherebysaid lamp is firmly maintained in said socket, but may be readilyremoved therefrom when desired.

4. In a lamp socket, the combination with a threaded lamp contact havingan aperture formed therethrough, of a friction shoe extending throughsaid gage the lamp base when a lamp is inserted into the socket, andmeans for exerting a spring pressure upon said friction shoe so as toforce the same against the lamp base, whereby said lamp is firmlymaintained 1n said socket but maybe readily removed therefrom whendesired.

5. In a lamp socket, the combination with a threaded lamp contact havingapertures formed therethrough at opposite sides thereof, of a pair offriction'shoes extending through said apertures so as to engage the lampbase when a socket, and a resilient device surrounding said threadedcont-act and engaging said friction shoes so as to force the latter intoengagement with the lamp base, whereby said lamp is firmly maintained insaid socket but may be readily removed therefrom when desired. 6. In alamp socket, the combination with a threaded lamp contact having aplurality of, apertures formed therethrough, of a plurality of frictionshoes, one extending through each of saidapertures, adapted to engagethe lamp base when a lamp is inserted into said socket, and a device forexerting a spring pressure upon said friction shoes to force them intoengagement with the lamp base, said device comprising a plurality ofspring straps attached to each other at the ends, so as to surround saidcontact, and bearingagainst said friction shoes.

aperture so as to enlamp is inserted into the 7. In an electric lampsocket, the combination with a threaded lam contact having a pair ofapertures formed herethrough, at opposite sides thereof, of a pair offriction shoes extending through said apertures so as to engage the lampbase when a lamp is inserted into said socket, and a device for exertinga spring pressure upon said friction shoes so as to force them intoengagement with the lamp base, said device comprising a pair of springstraps, each engaging one of said friction shoes, locked together attheir ends under a bending strain.

In witness whereof, I have hereunto subscribed my name in the presenceof two wit-

